Device for preventing obstruction of blast in blast-furnaces



2 Sheets-Shet 1.

(No Model.)

. J.M. HA'RTMAN. DEVICE FOR PREVENTING DESTRUCTION 0P BLAST IN BLAST FURNACES.

No. 570,129. Patented Oct. 27, 1896.

' UNITED PATENT OFF-Ion.

JoHN M. IIARTMA OFIPHILADELPHIA, PENNSYLVANIA.

DEVICE FOR PREVENTING OBSTRlJCTION 0F BLAST IN BLAST-EURNACES.

SPECIFICATION forming part r Letter s Patent No. 570,129, dated October 27, 1896. Application filed a, si, 1894. Serial No; 519,108. on) model.)

To all whom it may concern.-

Be it known that 1, JOHN M. HARTMAN, of Philadelphia, in the State of Pennsylvania, have invented certain new and useful Improvements in Devices for Preventing the Obstruction ofthe Blast in Blast-Furnaces and Insuring Proper Combustion.

The following is a specification of my said improvements, reference being had to the accompanying drawings, wherein- Figure 1 represents a vertical section through the twyer and adjacent operative parts, showing also a. portion of the wall of the blast-furnace. Fig. 2 is a front elevation of a portion of the furnace-jacket and its adjuncts. Fig. 3 is a vertical central section, on an enlarged scale, through the rear end of the twyer-pipe and adjacent working parts; and Fig. l is a rear View of the cap at the outer end of the twyer-pipe.

In practical blast-furnace operation there is usuallya substantially compact bed of fuel at and immediately above the zone of the twyers, since the reduction of the ore and formation of cinder take place at a higher level, and the metal and cinder drop down past the twyer-zone to the crucible.

The weight of the superincumbent mass of ore, fuel, and limestone tends to impact the fuel which is opposite to the twyer-zone and, by the formation of a core, prevent the blast from penetrating to the center. This core burns comparatively slowly, the impaction being usually intensified by the fact that at the high heats used the fuelbecomes pasty upon the outside of the core and thus forms a skin nearly impervious to the'blast.

In the rapid driving now practiced in this country the walls melt back above the twyers, this action occurring to a degree which leaves the water-cooled jacket exposed after a core is formed. The jacket usually becomes coated to a certain extent bycinder, (sometimes embedding pieces of fuel,) which chills and agglutinates, forming a coating upon the jacket and replacing to a certain extent the burnedaway wall. As, however, local changes occur in the temperature or other conditions of this regionthe bottom of this accidental coating often melts away immediately above the twyer and allows the portions above to' slide down, suddenly checking the air-blast by forming a skull over the twyer, and also exposing the iron jacket to injury.

My present improvements are addressed to the prevention of such slips in the region of the twyers and to remedying the injurious effects thereof when they do occur, as well as to the prevention of the formation of a core or other-obstruction opposite to the twyers from any cause.

I will now proceed to describe the same by reference to the drawings.

In Fig. 1, A represents the furnace-Wall; B, the twyer; B, the twyer-breast B the twyer-pipe O,the bustle-pipe, and O the blast pipe leading from the bustle-pipe to the twyerpipe near the rear end of the latter.

Adjacent to and above the twyer-breast is the jacket D, which is constructed in vertical sections having deep lateral flanges E, secured together by bolts 6. The inner face of the jacket D is provided with a series of abrupt horizontal flanges D at short vertical intervals, forming a practically continuous series of ledges around the interior of the jacket and extending into the wall as first built. .The exterior face of the jacket is provided with a series of horizontal watertroughs open at top, said troughs having at the ends where they join the flanges E guardpieces (1, which extend somewhat higher than the top of the rim of the trough, as indicated clearly in Fig. 2.

, Beneath the twyer breast a horizontal trough E is arranged to prevent the dripping of water down upon the crucible-jacket and undue chilling of the latter. At the rear end of the twyer-pipe is a cap or cover G, in which, and preferably in line with the axis of the twyer, is an opening g, having a rearwardlyprojecting circular wall H, provided with a is freely mounted to rotate in bearings M m, which projectrearwardly from the cap G of the twycr-pipe. Beneath the upper bearing M a lug n is also mounted upon the rear face of the cap G, said lug having a central notch n, adapted to receive the inner end N of the lever K and'lock the same against lateral displacement, the range of motion of the lever being such that when the outer end is lifted the inner end N can clear the sides of the notch 11, so as to set the lever free for rotation upon the vertical axis afforded by the pin L. At one side of the cap G is a rearwardly-projectin g lug a adapted to support the lever K when the same is turned laterally in that direction.

Opposite to the rear end of the twyer-pipe B andin the same axial line, is a cylinder P, having a piston P and pipes S S, arranged on opposite sides of said piston for the inlet and outlet of steamer other fluid to effect the rapid reciprocation of the piston.

To the front face of the piston is attached the prick-er-bar R, which extends through the front end of the cylinder in the proper relation to the rear end of the twyer-pipe for insert-ion through the opening gin the cover thereof when the same is exposed. The front end 0' of the prickenbar is preferably sharpened, and the length of the bar and stroke of the cylinder are such that the bar when protruded may penetrate deeply within the furnace. The cylinder may be mounted upon one of the pillars A, which support the mantel, and may he stayed against longitudinal thrust by means of the bar F, attached to the lug f upon the jacket or otherwise sustained in position.

The operation of the device is as follows: The ledges D upon the interior of the jacket provide local holds at short intervals for the chilled or agglutinated mass of cinder, &c., which forms in place of the burned-away wall, as previously described, said holds tending to prevent the slipping down thereof upon or in front of the twyer, and thus minimizing the formation of a skull or local obstruction at the mouth of the twyer. The watertroughs d (which are in themselves wellknown appliances) tend to maintain the cinder-coating in a chilled condition, and the only feature of invention which the present application embodies with reference to said troughs is the use of the projections d at the ends thereof which prevent the water from o\-'eri'lowing at the ends and trickling down upon the flanges E, where it is liable to leak into the joints between the flanges, an objection which has hitherto been found serious in the use of such troughs.

\Vhen a skull is found to exist in front of the twyer-nozzle, or when a core has formed within the furnace, the pricker-bar is brought into play in the following manner: The outer end of the lever K is lifted to clear its inner end from the notch n, the lever is swung around laterally, (away from the observer in the sectional views,) thus opening the valve J and exposing the interior of the twyer-pipe. At this moment the pricker-bar R is suddenly thrust into the furnace and instantly withdrawn before it has time to melt or soften, thus penetrating the skull or core directly in line with the entering blast and enabling the latter to follow freely through the hole formed by the insertion of the pricker-bar. As soon as the bar is withdrawn the valve J may be immediately replaced, thus preventing the escape of the blast.

I am aware that the use of internally-projecting ledges to maintain the masonry of a furnace-wall is not broadly new, and that closed conduits have been used in structures embodying such method of construction.

I am also aware that horizontally-projectin g strips of conducting metal have been inserted into the wall of a furnace, said strips terminating in troughs exterior to the wall, in order to conduct away heat from the adjacent portions of the wall. I do not claim either of these devices, nor are the same adapted to the purpose of my invention. The use of a closed conduit in connection with a furnacej aeket is always attended with serious danger in the event of a crack or leak, since the water is liable to flow into the furnace and produce an explosion. This danger is entirely avoided by the use of the comparatively shallow open water-trough which I employ, since in the event of a leak from the cracking of the jacket the gas within the furnace will blow out into the air and be at once detected. The use of isolated conductingstrips, even though provided with an external trough, in no way meets the purpose of my invention, since there is no jacket to bind the structure together, and in the event of the eating away of the wall to any serious extent the strips would lack external support.

I am also aware that the use of prickerbars operated by hand is not new for the general purpose of breaking up obstructions in or adjacent to the air-passage, and I do not broadly claim the same. I believe, however, that I am the first to devise an organized apparatus for the mechanical operation of such bars by power and to provide a means whereby the power may be rapidly and powerfully operated, thus preventing the softening or melting of the bar itself and rendering the apparatus highly efficient under the difficult conditions of temperature, the, which attend the use of such a device in a blast-furnace.

I clai1n-- 1. The combination with the furnace-wall of a jacket constructed in vertical sections; a series of internally projecting flanges mounted upon said jacket above the twyerbreast; a series of open, horizontal watertroughs arranged upon the exterior of said jacket; and guard-pieces at each end of said troughs extending above the level of the remainder of the rim portion thereof, substanpin carrying said lever, as and for the purtially as set forth. poses specified.

2. The combinati0n,With the blast-furnace, r1 twyer pipe and prieker bar, of a valve OHN HARlMAN' 5 mounted in the rear end of the twyer-pipe a Witnesses:

Weighted lever normally supporting said JAMES H. BELL, valve in a closed position; and a rotatable G. HERBERT JENKINS. 

